Duplex flowrate valve for pressurized fluids

ABSTRACT

TWO FLOWRATE CONTROL VALVES FOR HYDRAULIC SYSTEMS HAVING RESPECTIVE ROTARY THROTTLE VALVES ARE JOINED BACK-TO-BACK COAXIALLY IN TANDEM ALONG THE AXIS OF THE THROTTLE VALVES, WHICH COMPRISE CUTOUTS POSITIONED IN TANDEM ON A COMMON VALVE BODY AT SYMMETRICAL POSITIONS WITH RESPECT TO THE AXIS, ONE OF THE FLOWRATE CONTROL VALVES BEING PROVIDED WITH A BYPASS CHECK VALVE. THE RESULTING COMBINATION IS A DUPLEX FLOWRATE CONTROL VALVE OPERABLE BY A SIGNAL MANIPULATION AND WHICH CAN BE USED TO VARY THE SPEED OF HYDRAULIC FLUID-DRIVEN DEVICES WITHOUT THE ADVERSE OCCURRENCES UNAVOIDABLY ACCOMPANYING CONTROL WITH A SINGLE CONTROL VAVLE.

United States Patent 1,896,092 2/1933 Mangiameli Inventor Torao Namiki492 Nishihori, Urawa-shi, Saitama-Ken, Japan Appl. No. 751,812

Filed Aug. 12, 1968 Patented June 28,1971

DUPLEX FLOWRATE VALVE FOR PRESSURIZED FLUIDS 6 Claims, 8 Drawing Figs.

US. Cl 137/595, l37/625.l9, 91/443, 91/447 Int. Cl Fl5b 11/04 Field ofSearch 91/443, 447, 463; l37/625.l8, 625.19, 595

References Cited UNITED STATES PATENTS 2,272,684 2/1942 Vickers 9l/447X2,328,980 9/1943 Herman et al.. 9 l/463X 2,437,139 3/]948 Tucker137/625,l9X 2,476,763 7/1949 Pettibone 9l/447X 2,974,637 3/1961 Holmeset al. 9l/443X Primary Examiner Robert G. Nilson Attorney-Waters, Roditiand Schwartz PATENTEDJUN28I97I I 3,587,639

FIG. I

I I L6) A I I I 8 5 051 I 2 FIG. 2 FIG. 3 FIG. 4

FIG. 7 FIG. 8

DUPLEX FLOWRATE VALVE FOR PRESSURIZED FLUIDS BACKGROUND OF THE INVENTIONThis invention relates generally to hydraulic (fluid pressure) systemsand more particularly to a new duplex flowrate control valve forpressurized fluid in hydraulic systems.

In hydraulic system organizations such as that wherein hydraulic fluiddelivered from a pump is supplied by a powerdriven, reciprocatingswitching valve alternately to the two heads of a double-actinghydraulic motor of piston-andcylinder type to cause the piston rod ofthe piston to undergo reciprocating motion, it is frequently necessaryto change the speed of the piston rod. This can be accomplished byvarying the flowrate of the fluid flowing through the hydraulic circuit,and two or three methods of using a single flowrate control valve forvarying'this flowrate are already in use.

The use of a single flowrate control valve, however, is accompanied bycertain disadvantageous occurrences such as increase in the speeds ofthe driven parts with decrease in the load on the motive power motivepower means or a rise in the fluid temperature and excessive load on themotive power means as will be described more fully hereinafter.

SUMMARY OF THE INVENTION It is an object of the present invention toeliminate the above mentioned disadvantageous occurrences accompanyingthe use of a single flowrate control valve in a hydraulic configurationof the above described character.

According to the present invention, briefly summarized, there isprovided a duplex flowrate control valve for pressurized fluidscharacterized by the combination therein of two flowrate control valveshaving respective throttle valves and valve boxes joined together intandem alignment with one valve box structurally inverted back-to-backvrelative to the other valve box, one of the control valves beingprovided with a bypass check valve, the throttle valves being joinedintegrally in coaxial tandem arrangement to form a single combined valvebody having cutouts constituting operative surfaces of the throttlevalves and symmetrically positioned with respect to the axis of thecombined valve body, the combined valve body being inserted incorresponding valve chambers within the valve boxes.

The nature, principle, details, and utility of the invention will bemore clearly apparent from the following detailed description withrespect to a preferred embodiment of the invention when read inconjunction with the accompanying drawing, in which like parts aredesignated by like reference numerals.

BRIEF DESCRIPTION OF THE DRAWING In the drawing:

FIG. 1 is a schematic diagram showing an example of a hydraulic circuitincluding flowrate control valves, which in combination constitute theduplex control valve of the invention, a hydraulic driving member, and adriven member;

FIG. 2 is a relatively enlarged, longitudinal sectional view of achangeover valve in the system illustrated in FIG. 1;

FIGS. 3 and 4 are relatively enlarged sectional views of examples of twoflowrate control valves suitable for combination to form a duplexcontrol valve according to the invention;

FIG. Sis a front view of the duplex flowrate control valve;

FIG. 6 is an enlarged perspective view showing a single combined valvebody of the throttle valves of the duplex control valve; and

FIGS. 7 and 8 are cross sections respectively taken along the planesindicated by lines (7)-(7) and (8)-(8) in FIG. 6.

DETAILED DESCRIPTION Referring first to FIG. I, the hydraulic systemillustrated therein consists, essentially, of a hydraulic circuitcomprising a power-driven reciprocating changeover valve 3, a flowratecontrol valve A, a hydraulic motor 7 with a piston 7a, and a flowratecontrol valve B provided with a check valve 8 functioning as a bypassvalve. A pump 2 driven by an electric motor 1 is connected to supplypressurized fluid to the changeover valve 3.

When pressurized fluid is thus delivered from the pump 2 to thepower-driven reciprocating changeover valve 3, shown in detail in FIG.2, the fluid is delivered alternately from delivery ports 4 and 5 of thevalve 3. At the same time, return-flow pressurized fluid is dischargedfrom a discharge port 6, and piston 7a is caused to undergoreciprocating motion.

The speed of this reciprocating motion is varied, according to theinvention, by installing the flowrate control valve A and the flowratecontrol valve B with the check valve 8 in the hydraulic circuit as shownin FIG. 1. The valve B as shown in detail in FIG. 4 is similar inconstruction and operation to the valve A as shown in detail in FIG. 3except that it includes the check valve 8. Valves A and B are providedrespectively with similar throttle valves 9 and 10 and similarcompensator valves 12 and 12a.

The flowrate control valves A and B differ in that, whereas a decreasein the degree of opening of the throttle valve 9 in the control valve Acauses a decrease in the flowrate of fluid flowing out from thehydraulic circuit and an increase in the flowrate of the fluid withinthe circuit, a decrease in the degree of opening of the throttle valve10 in the control valve B causes a direct reduction of the flowrate ofthe fluid within the circuit. Therefore, if the control valves A and Bwere to be used together but respectively in their independent states,it would be necessary to turn their throttle valves 9-and 10 inrespectively opposite directions for accomplishing control of theflowrate of the fluid through the circuit.

Accordingly, in a preferred embodiment of the invention, the twothrottle valves 9 and 10 are constructed integrally in tandem asillustrated in FIG. 6 or coupled in coaxial tandem arrangement to form asingle combined valve body in which circumferential recesses or cutouts9a and 10a, respectively, of valves 9 and 10 are in symmetricallydisposed left and right positions as indicated in FIGS. 7 and 8.

Furthermore, the valve box of one of the control valves A and B as shownin FIGS. 3 and 4 is inverted structurally relative to the other, thatis, as though one valve box were turned through l of angle about avertical axis, and the two valve boxes are thus joined back-to-back intandem to receive the aforedescribed combined valve body of throttlevalves 9 and 10. By turning a knob 11 affixed to one end of the combinedvalve body, flowrate control due to both control valves A and B can becarried out by a single manipulation.

Each of the aforementioned compensator valves 12 and 12a operates tomaintain constant the difference between the pressures on the upstreamand downstream sides of the corresponding throttle valve and tostabilizethe flowrate of the fluid through the hydraulic circuit.

When only the control valve A is used, the flowrate control isaccomplished by discharging fluid out of the hydraulic circuit. For thisreason, a rise in the fluid-temperature does not occur, and the electricmotor 1 for driving the pump 2 is not subjected to excessive load.However, the speeds of driven parts such as the piston rod 7adisadvantageously increase when the load decreases. On the other hand,while the use of only the control valve B is effective in the control ofthe speed of the driven parts, it is accompanied by disadvantageousoccurrences such as a rise in the fluid temperature and excessive loadon the motor.

Thus, the present invention, as described above with respect to apreferred embodiment thereof, overcomes the above described difficultiesarising when only one control valve is used.

It should be understood, of course, that the foregoing disclosurerelates to only a preferred embodiment of the invention and that it isintended to cover all changes and modifications of the example of theinvention herein chosen for the I purposes of the disclosure, which donot constitute departures from the spirit and scope of the invention asset forth in the appended claim.

lclaim:

l. A control valve comprising a pair of throttle valves adapted forconnection in a common hydraulic circuit, each of said throttle valvescomprising a housing provided with a throttle port and inlet and outletchannels communicating with the respective throttle port, each saidhousing being connected in tandem to the other such that each respectivethrottle port communicates coaxially with the other, and a commonthrottle-shaft regulator supported longitudinally in both of thecoaxially communicating throttle ports, said common throttleshaftregulator being provided with a pair of spaced recesses each cooperatingwith each of said throttle ports respectively such that a singlemanipulation of said common throttle-shaft regulator increases the openport area of one of said throttle ports and simultaneously decreases theopen port area of the other of said throttle ports, one of said throttlevalves including bypass means for bypassing a fluid when its associatedopen port area is decreased by said regulator.

2. A control valve as claimed in claim 1 wherein each of said housingsincludes a front portion and a back portion, said inlet and outletchannels and said throttle port of each of said housings beingidentically arranged with respect to the respective front portionthereof, said housings being connected to one another in back-to-backrelation.

3. A control valve as claimed in claim 1 wherein one of said throttlevalves includes a bypass check valve.

4. A control valve as claimed in claim 1 wherein said housings areinverted 180 relative to one another.

5. A control valve as claimed in claim 1 wherein said pair of spacedrecesses are each circumferentially disposed in said throttle-shaftregulator.

6. A control valve as claimed in claim 5 wherein said spaced recessesare each symmetrically disposed relative to the longitudinal axis ofsaid throttle-shaft regulator.

